Recently, an improvement in the fuel consumption of automobiles (namely, lowering of fuel consumption) has been desired by the request of the environmental protection. In the field of automobile tires, it is known that the fuel consumption of automobiles goes down by improving the viscoelastic property of vulcanized rubber used for tire production (see, “Rubber Technology Introduction”, p. 124 edited by The Society of Rubber Science and Technology, Japan, published by Maruzen Co., Ltd.).